1. Field of the Invention
The present invention relates to an imaging device and a focus-confirmation display method that display an image (hereinafter also referred to as a “split image”) to be used for focus-confirmation during manual focusing.
2. Description of the Related Art
There is a well-known digital camera provided with an autofocus function using a phase difference detection method or a contrast detection method along with a so-called manual focus mode in which a user can manually adjust focus. There is a well-known digital camera with a manual focus mode using a method as follows: a method in which a reflex mirror is provided so that focus can be adjusted while a photographed subject is checked, and a split microprism screen is used to display visual phase difference; and a method in which contrast is visually checked.
In a digital camera without a reflex mirror that has become wide spread in recent years, there is no method of checking a subject image while displaying phase difference because no reflex mirror is provided. As a result, focusing has to rely on a contrast detection method. In this case, however, it is impossible to display an image with contrast higher than that in resolution of a display device such as an LCD, so that a method of partially enlarging the image has to be used to display the image.
Thus, in recent years, a split image (focus-confirmation image) is displayed in a live view image so that an operator can easily focus on a subject at the time of a manual focus mode. The split image is formed by combining two subject images (two phase difference images) acquired by a pupil-split method to show phase difference between the subject images. That is, there is displayed a split image in which an upper half of one of the subject images is vertically adjacent to a lower half of the other of the subject images. In a state where the images are out of focus, the two subject images vertically adjacent to each other are deviated right and left, and in a state where the images come into focus, there is no deviation in the right and left of the two subject images vertically adjacent to each other. The operator operates a focus ring so that there is no deviation in the right and left of the two subject images in the split image, thereby focusing on the subject.
Japanese Patent Application Laid-Open No. 2004-40740 (hereinafter referred to as PTL 1) describes a digital camera in which an aperture is moved in an optical axis and a vertical direction so that a subject image is photographed at each of two ranging positions to display a split image in a live view image by using two images of the subject at the two ranging positions.
Japanese Patent Application Laid-Open No. 2001-309210 (hereinafter referred to as PTL 2) describes a digital camera in which a value corresponding to a distance between an image surface of a subject image and a receiving surface of an imaging element is acquired as the amount of deviation so that, in a live view image, there is displayed a split image in which images are displaced in respective right and left directions opposite to each other in accordance with the amount of the deviation.
Japanese Patent Application Laid-Open No. 2009-147665, Japanese Patent Application Laid-Open No. 2009-163220, and Japanese Patent Application Laid-Open No. 2009-276426 (hereinafter respectively referred to as PTL 3, PTL 4, and PTL 5) describe digital cameras each of which includes an imaging element in which a plurality of normal pixels for photographing, and a plurality of two types of phase difference pixel for detecting a focus that receive subject light beams to which pupil-split is applied, are arranged on an imaging surface. The digital camera creates a photographed image on the basis of an output signal from each of the normal pixels to display a live view image, as well as creates a split image on the basis of output from each of the two types of phase difference pixel to display the split image in the live view image.
In addition, PTL 5 discloses a split image in which a position of each of images is changed, a split line whose directions are changed, and a split image that is enlarged.